Prevention strategies that aim to test and treat people for HIV infection are undermined by HIV treatment non-adherence and sexually transmitted co-infections (STI). Scalable interventions are urgently needed to sustain low infectiousness by improving HIV treatment adherence and reducing risks for transmitting HIV. This application proposes to test a theory-based behavioral intervention to simultaneously improve HIV treatment adherence and reduce HIV transmission risk behaviors in people living with HIV/AIDS who use alcohol and other drugs. Grounded in Conflict Theory of Decision Making, the intervention will be delivered in a mixed format, with one office-based counseling session followed by four cell phone delivered counseling sessions. The intervention will be conducted in Atlanta and surrounding impoverished areas. Men (n = 250) and women (n = 250) receiving HIV treatment will be recruited from AIDS services and infectious disease clinics. Following informed consent and baseline assessments, participants will be randomly assigned to either an (a) integrated HIV treatment adherence - risk reduction intervention or (b) a time-matched non-contaminating attention control condition. Participants will be followed for 12-months using office-based computerized interviews, unannounced pill counts, and medical chart abstraction. The study will test the hypothesis that a unified, integrated theory-based HIV treatment and risk reduction intervention will reduce HIV transmission risk behaviors, improve HIV treatment adherence, reduce viral load and prevent new STI. The study will also examine the influence of theoretical constructs and structural barriers on intervention outcomes. Factors that predict relapse to non-adherence and risk behaviors in relation to changes in viral load and STI over the 12-month follow-up period will also be a focal point of the study. The intervention under investigation will be among the first to simultaneously address treatment adherence and risk behavior in an integrated model for substance using HIV positive men and women. If shown effective, the intervention model will be ready for immediate dissemination to community and clinical services for people living with HIV/AIDS.